As is well known, to improve the sharpness of a color photograph; that is, to make the definition of an image high, it is effective to make the layer of a silver halide color photographic light-sensitive material thin. Recently there has been increased demand for photographic processing to be made simple and rapid. To meet this demand of processing speed enhancement, it is also effective to make the layer of a light-sensitive material thin.
Research on photographic couplers has been eagerly conducted. For example, as a magenta coupler, U.S. Pat. No. 4,540,654 and the like disclose 1H-pyrazolo[1,5-b]-1,2,4-triazole couplers and U.S. Pat. No. 3,725,067 and the like disclose 1H-pyrazolo[1,5-c]-1,2,4-triazole couplers, respectively, that give good magenta dyes. JP-A-1-302249 (“JP-A” means unexamined published Japanese patent application) and JP-A-6-43611 disclose that the color image fastness of a 1H-pyrazolo[1,5-b]-1,2,4-triazole coupler having a tertiary alkyl group in its 6-position, and a phenylene group in its 2-position, is improved compared with conventional couplers. However, when rapid processing suitability is given, and the definition of an image is made higher by making the layer thin, these pyrazolotriazole magenta couplers are not necessarily satisfactory. For example, when the solubility of such a coupler itself in a high-boiling-point organic solvent is low, it is necessary to use this solvent in a large amount. This runs counter to the thinning of such a layer as mentioned in the above. Even if such a coupler can be added to an emulsion layer of a light-sensitive material, the coupler may be precipitated when the light-sensitive material is stored prior to being subjected to development processing with the lapse of time. Thus, the solubility of such a coupler is an important task to be attained.
On the other hand improving the storability of a color image, in particular the fastness of a color image to light, is also an important task for color photographs used for preserving records. For example, U.S. Pat. No. 3,725,067 and the like propose a 1H-pyrazolo[1,5-c]-1,2,4-triazole magenta coupler. However, further improvement in the fastness to light is desired, since the demand for improving fastness to light is intense.
Further, an important task in development of a coupler is whether it is possible or not to produce inexpensively a coupler having both of the above-mentioned solubility and fastness to light.